"No one knows this … I had a miscarriage for the two weeks that I took off," said an emotional Lohan during the final moments of Sunday night's finale.

Lohan didn't say who the baby's father was.

"It's a very long story, but that's why on the show when it says she doesn't want to come down, I couldn't move; I was sick. Mentally, that messes with you," she added. "Watching this series, I just know how I felt at that moment, and I can relate to that girl, which sounds kind of crazy, but I'm like, 'Oh my god, this is really sad. Who's helping her?' "

She continued: "Even if it's not my intention to lose everything I've worked for, that's what my addiction will do to me … It's a really f--ked-up disease, and it's really scary. Because there are drugs people have said that I've done that I've never touched."

Lohan also said that she's glad she agreed to film the show. The actress, who recently guest-starred on CBS' Two Broke Girls, also is set to start filming her next movie, the psychological thriller Inconceivable, in the summer.

"I'm happy," she said. "The biggest thing I learned from this experience and doing this show is my work ethic is different. I have that fire back in me."